On December 3, 2018, the NRC issued a Notice of Violation and Proposed Imposition of Civil Penalty in the amount of $3,500 to Christiana Care Health Services (licensee) for a Severity Level III violation of 10 CFR 20.1802. Specifically, as of March 16, 2018, the licensee failed to control and maintain constant surveillance of licensed material, unused Iodine-125 seeds, that was in a controlled or unrestricted area and not in storage. On May 30, 2018, the licensee discovered that unused Iodine-125 seeds were missing. A search was conducted for the missing material; however, the licensee was unable to recover the material and determined that the material was dropped into the facility waste container.